The invention is related to a method of processing a ceramic electrolyte. The invention is also related to devices made therefrom.
Solid oxide fuel cells (SOFCs) are promising devices for producing electrical energy from fuel with high efficiency and low emissions. One barrier to the widespread commercial use of SOFCs is the high manufacturing cost. The manufacturing cost is largely driven by the need for state-of-the-art ceramic anodes, cathodes, or electrolytes, which allow the fuel cells to operate at high temperatures (e.g., about 800° C.). Fuel cell components that can meet these criteria require materials of construction that can be expensive to manufacture. Solid oxide fuel cells need to have high power densities and fuel utilizations, and need to be large in size, in order to make the technology economically feasible.
Thermal spray processes, such as air plasma spray, have the potential to provide large-area cells on interconnect supports that may reduce manufacturing costs. However, air-plasma-sprayed coatings typically contain both porosity and microcracks, which in the case of a ceramic electrolyte may provide leak paths for the fuel and air. Microcracks are typically formed at interlamellar splat boundaries during deposition, or are formed through the thickness of the coating, due to large thermal expansion strains caused during deposition. Such defects may limit the open cell voltage and fuel utilization. Therefore, there is a continuous need to improve the performance of a ceramic electrolyte and versatile methods to process ceramic electrolytes.